Marginal brick.



E. P. STEVENS.

MARGINAL BRICK.

APPLICATION FILED FEB- II. I916.

Patented June 12, 19W.

' tor locomotive firebox arches,

ENOCH P. STEVENS, OF CHICAGO, ILLIH 01S, ASSKGNOE T0 AMERICAN ARCH COMPANY, 01: NEW YGRK, N. Y., ll. CORPORATION OF DELAWARE.

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Specification of Letters Patent, Patented; June 12, 191?;

Application filed February 11', 1916. SeriallNc. 77,646.

To all whom it may concern:

Be it known that I, Enocn P. STEVENS,

a citizen of the United States, residing at Chicago, in the county of Cook and State of I Illinois, have invented certain new and useful Improvements in which the following is a specification.

My invention relates to 'front arch collstructions for locomotive firebones and has special reference to improvements in the marginal bricks of such arches. A primary object of my invention is to improve the construction of marginal arch bricks in a manner to adapt a marginal single brick for use,in many did'erent positions, In other words, to broaden the working range of such bricks. A marginal-brick occupies the space between. the outermost water circulating arch tube and the adjacent side sheet of the thebox. Even in a single firebox the distance between the arch tube and the side sheet varies from end to end of the box. "It has been the practice to install marginal bricks upon the tubes and against the side sheets and to compensate for the varying distance between the side shwt and arch tube by the the locomotives, and l perceive that the dimculty encountered in ordinary practice may be obviated by modifying the primary form of such marginal bricks in such manner as to adapt them to act properly in many different positions and various inclinations upon the arch tubes and side sheets. 1

v With this end in view, I have devised, and my invention consists in, a marginal brick having anend formed to rest upon an arch tube and barinn; an under or outer side for engagement with the side sheet of a firebox, and which substantially conforms to the arc of a circle which extends from end to end or the brick. "While the special shape here defined is the most desirable form for the brick, the following description will show that the invention is not specifically limited to a brick which is-curved in conformity with a true are oi a circle,

Marginal Bricks, of-

' box side sheet in cornbinationiwith a main cally dotted line, 2,

My ini ention will be readily understood on reference to the drawings which form part of this specification; and in which, Figurel is a vertical transverse section of a portion ofa locomotive firebox, discloslng two Water-circulating arch tubes and a firearch brick and a marginal brick, embodying my invention;-Fig. 2 is a plan view of the marginal brick inverted to show the bottom Further referring to the drawings, 2 represents one or the side sheets of a locomotive firebox ;3 is the outermost arch tube and 4 is an intermediate arch tube. lit will "be understood that these arch tubes are in substantial'parallelism with the side sheet, 11's., longitudinally of the firebox.- lt'will also be understood that thearch tubes are inclined forwardly and downwardly in the firebox.

The main or arch body brick, A, may be of any suitable design, but preferably has tubes, 3, and 4. So far as the present invention is concerned, it is only necessary that the body brick, A, shall be of a formation and weight sufficient to cause it to maintain itsposition on the arch tubes, 3 and 4:. This is necessary because, as hereinafter explained, the end. portion, a of the brick serves as an abutment for the marginal brick, B. Asbefore stated, the distance between the tube, 3, a'nd'the side sheet, 2, often variesin diderent parts of the same firebox,

due to the fact that the arch tribe, 3, is in substantial but not strict parallelism with the side shoot it is also well known that there is at present no standard or determined spacing for the arch tube and side sheet, and hence difi'erent spacings are en countered in practically every locomotive in which arch bricks are installed. l, have indicated a variation in spacing by the vertiwhich represents another side sheet in a difierent location with respect to the outertube, 3..

The brick, B, is of a width substantially the same as that. of the brick, A. At its in nor end it has a bearing cornw or rib, 5'. Starting from this oint, the bottom of the brick is curved pre erably upon a line, 15 which. is substantially the same the curvagsocketed ends, .a, engaged with respective brick to be elevated to the position shown by the locomotive.

ture of the circumference of the tube, 3. From that point the curve of. the bottom conforms to an arc of a circle,b which continues uninterruptedly to the end, 6*, of the brick. Obviously, thebottom, which, is so curved, is adapted to co-act with the side sheet in any tangential position in which ting portion, a', of the body brick with j which the brick, B, is to be used. As a rule,

the end,'b is disposed'at an obtuse angle to the top surface, 6 That form allows the dotted lines, or further, without interference,

with the upper corner of the body brick, A;

In the preferred construction of the brick,

B, the middle thereof is of the greatest thickness and the thickness diminishes toward the free end, I).

' ll reduce the bearing .of the brick upon the sijde sheet virtually to a single point by thinning the brick from its middle line toward its edges, leaving only a broad middle rib, b", to bear against the side sheet, as best shown in Fig. 3. The strength of the brick is retained by merging the rib with the body of the brick adjacent the inner endthereof. This crescent-like marginal brick piyots freelyupon-the'top of the arch tube, 3, and against the end of the brick, A. It is notonly capable of use in various positions, as explained, but also adapts itself to the.-

changes which take place between the side sheet and the tube, 3, during the working of It will doubtless. occurto the reader that the top of the marginal brick might better conform to the straight dotted line D, and

indeed the brick may be so formed, but in that. case it"will be found that the weight of the brick represented in full lines is much brick resting thereon.

- In testimony whereof, I have hereuntoto b e preferred, and furthermore I find that the crescent formed brick is stronger by reason of the fact that a brick of that form is more uniformly burned in the kiln and is 'not subjected to the effects of uneven shrinkage.

Having thus described my invention, ll

claim as new and desire to secure by Letters Patent:

1, A marginal, brick for locomotive firebox arches having its bottom substantially conformed to a single arc of a circle extending from 'end to end thereof, save that the inner end of said brickis provided with a 'downturned bearing-rib for co-action with an arch tube and the end of an. archbody brick thereon.

2. A marginal arch, brick of crescent-like form in side elevation and having its inner end formed for engagement with the top pf an arch tubeand'the end of an arch body brick.

' 3. A marginal arch brick of crescent-like 'form in side elevation andhaving a bearing rib at its inner end adapted for engagement with the top of an arch tube and the end of an arch body brick'thereon.

' 4'.- A marginal arch brick of crescent-like form having a middle-bearing rib on its bottom and at its inner end provided with a bearing rib at right angles to said middle rib whereby the inner end of said brick is adapted-for support by an arch tube and for engagement withan arch body. brick resting thereon.

5. A marginal arch brick of crescent like form having a middle bearing rib on its bottom and at its inner end provided with a bearing rib at right angles to said middle rib adapting said end for engagement with the topof an arch tub'eand'an arch body brickthereon, and the 'inner end ofv said brick being formed at an obtuse angle to the top of the brick whereby theinner end of said brick is adapted for support by an arch tube and engagement with an arch body set my hand this 25th da of Januar 1916.

ENOC. P. STE NS. 

